1. Field of the Invention
The present invention relates to a colorant compound and an ink including the colorant compound.
2. Description of the Related Art
Water-soluble dyes are generally used as colorants in ink jet recording liquids (inks), but a problem associated with recorded images formed by inks including water-soluble dyes is that the images have poor stability in storage. Thus, problems are associated with discoloration of images caused by solar light or various types of illumination light (light fastness) or discoloration of images caused by oxidizing gases (ozone, NOx, SOx) contained in very small amounts in the atmosphere (gas resistance). Furthermore, when photographic images or the like are outputted, problems are associated with color developing ability.
A pyridone azo colorant compound has been suggested as a water-soluble yellow dye for ink jet recording with the object of resolving the above-described problems (Published Japanese translation of a PCT patent application No. 2003-510398). A pyridone azo yellow colorant compound has also been suggested for applications other than inks for ink jet recording (Japanese Patent Laid-Open No. 2006-071822).